Alvarez went deep in the first inning, his first at-bat at McKechnie Field as a visiting player. Reimold followed with a long shot to left-center off minor league call-up Trevor Williams.
Selected by the Pirates second overall in the 2008 amateur draft, Alvarez signed with the Orioles three weeks ago as a free agent. He was not in the lineup the previous time the Pirates hosted the Orioles this spring.
''I'm very sensitive to that,'' Baltimore manager Buck Showalter said. ''When he first got to us, I would never ask him about playing against the Pirates or whatever. We had one opportunity where we didn't, just to kind of let him get settled in a little bit. I think he's handled it real well.''
Josh Harrison blooped a two-run triple, one of four hits the Pirates got off right-hander Ubaldo Jimenez in the first inning. Jimenez lasted just two-thirds of an inning, allowing three runs on four hits and a walk. He has a 12.27 ERA.
''I didn't have good command of the fastball,'' Jimenez said. ''I was falling behind in the count, and they made me pay for it. You're never happy to be out of the game in the first inning. It doesn't matter if it's a Little League game or a major league game.''
It was the second time this spring Jimenez did not make it out of the first inning. He managed only one out and gave up six runs on March 2 against Atlanta.
Orioles: To make up for his abbreviated outing, Jimenez got up three times in the bullpen after he left the game to simulate a longer start.
''I think I threw too many pitches, close to 40,'' Jimenez said. ''They didn't want me to go that far, especially in spring training.''
Pirates: Williams worked the first five innings. He allowed two runs on seven hits and struck out five. The right-hander, a non-roster invite to big league camp, likely will begin the season at Triple-A Indianapolis.
''It was a nice surprise to come up here and pitch under the lights,'' Williams said. ''When you come into big league camp and look at guys you've been watching your entire life, you realize how close you are. It was tangible tonight, getting big leaguers out.''
MORE THAN EXPECTED
Pirates RHP Juan Nicasio threw 98 pitches over six innings in a minor league game. Although he was signed to be a long reliever, Nicasio has performed well enough in camp to be in the mix for a rotation spot.
''I'm happy, no matter what my role,'' he said. ''My arm is sharp, my body feels strong.''
Orioles: INF Ryan Flaherty was scratched from the lineup due to flu-like symptoms. . Showalter said he's confident C Matt Wieters, who played in an intrasquad game, will be ready for opening day. Wieters hasn't caught in a major league game since his right elbow flared up on March 12. . LHP Brian Matusz (back) threw in the intrasquad game and will throw again on Monday. . INF-OF Jimmy Paredes (wrist) isn't sure if he'll remain in Florida when the team heads north.
Pirates: SS Jordy Mercer knocked his left knee hard on third base while sliding. He left in the fourth inning as a precaution and is not expected to miss any time. . RF Gregory Polanco (shoulder) and LF Starling Marte (tight quad) were not in the lineup, but neither injury is expected to keep them out of action for more than a day or two longer.
Orioles: RHP Dale Thayer opted out of his minor league contract and left the Orioles. Baltimore has 42 players left in camp.
Pirates: LHP Eric O'Flaherty was dealt to the Atlanta Braves for cash. O'Flaherty appeared in eight games with a 2.89 ERA and a 1.82 WHIP this spring. The move could mean Cory Luebke will be the second lefty, along with setup man Tony Watson, in the opening-day bullpen. If he is not assured a spot on the active roster by Tuesday, Luebke can trigger an out clause in his contract.
JUST GOT HERE
Orioles OF Hyun Soo Kim said he's not aware of reports that Baltimore has discussed allowing him to return to South Korea. Kim said he's happy he accepted a $7 million, two-year offer to come to the Orioles. Showalter had no comment on the Foxsports.com report.
''He's competing,'' Showalter said. ''You know what? That's not completely true. We'll see what the next few days bring. We've got some tough decisions to make.''
Orioles: RHP Mike Wright starts Monday against the Boston Red Sox.
Pirates: RHP Gerrit Cole will pitch Monday against the Minnesota Twins. Slowed by a sore ribcage at the start of camp, Cole has appeared in one Grapefruit League game, a two-inning stint March 13 against Detroit.